This invention relates generally to a pillow block and more particularly to a one-piece metal pillow block.
Present day pillow blocks are primarily of two types: one-piece machine castings in gray, ductile or malleable iron, and two-piece stamped sheet metal pillow blocks. There are also a few light-duty stamped, plastic or rubber-lined units available.
The cast types are relatively expensive to process through the steps of casting and machining to provide a bearing mount having tolerances compatible with the typical heavy duty service for which they are applicable. Generally, they can only be mounted by bolts and the surface on which they are mounted must be flat or the pillow block may fracture when the bolts are tightened. The most popular types are cast iron which are sensitive to shock loads.
Typical of the prior art stamped units are those shown in U.S. Pat. Nos. 2,467,994; 2,654,645; and 3,552,808. In all instances these pillow blocks are formed of lightweight material and are of two or more piece construction. These pillow blocks are primarily used for light-duty applications.